Liverpool appeared to be feeling the effects of a punishing 1200-mile trip but Benitez remained defiant as he claimed Liverpool should have had an equal i ser through Yossi Benayoun.
He added: 'It was a difficult match. I would have loved to have attacked more to have created more chances, but without Fernando Torres that was difficult.
Face off: Rafa Benitez has words with ref Laurent Duhamel after Benayoun's effort was ruled out
'We had two or three good chances, and we also had a goal disallowed that was clearly onside. The player said he was ons ide, so we ar e disappointed.
'I'm not happy, because it could have been a better result, but I am not unhappy either, because the game will be decided back at Anfield, and with our fans behind us, we know we can do it. I am confident now of reaching the final. I have a lot of confidence at Anfield and a lot of confidence in our fans.
'In the past we have come from behind in the first leg to reach finals, so we are quite positive. We have already come from behind against Benfica and Lille.
'No one is favourite now. We know it will be difficult. We know we need the right approach, and we can do better and score goals at Anfield.'
Way to go: Liverpool trio Steven Gerrard, Lucas Leiva and Dirk Kuyt try to find a way through Atletico defence
Liverpool are no strangers to needing European comebacks.
In the quarter-finals they trailed 2-1 after the first leg against Benfica before claiming a 5-3 aggregate victory, while in the last 16 they also lost the first meeting 1-0 against Lille before going through 3-1.
'We've been in the same situation before and we've found out we can win, so hopefully it will be the same again,' added Benitez.
'I also think in the past we've been losing 1-0 in games down the years and we were in that final, so that's quite positive.
Eyes wide shut: Forlan prods past Reina to open the scoring
'We know that it will be difficult because 1-0 is always a dangerous score, but we are still confident.
'We've done it in the past and we have to approach the game with this confidence and it would then be easier for us to play better and to score more goals.'
Atletico coach Quique Sanchez Flores, whose side had lost their previous three games coming into tonight's match, was also in confident mood for the return meeting.
'It was an intense game, very tiring. A second goal would have completed the match but we can't complain,' he said.
Red devil: Former United striker Diego Forlan celebrates early strike for Atletico
'One-nil is a good result, the dressing room is optimistic but we know the game will be decided in the second leg.
'We need to play a good second leg as Liverpool will come out strongly.'
When asked if he thought Liverpool's performance was disappointing, Sanchez Flores added: 'They probably feel they didn't play a good match but they fought and only lost by a narrow margin.
'Even in their worst matches they score a six out of 10, they never disappoint.'
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